The subject of the present invention is a device for the preventive treatment of dental decay by means of the mechanical action of massaging the enamel, of the type comprising a tool-holder provided with a head to which a massage cup or brush is connected, the said tool-holder incorporating on the inside means for driving the cup or brush in alternating rotation about its axis, the tool-holder incorporating on the inside means for converting a continuous rotational movement of the drive shaft into an alternating movement transmitted by the head of the tool-holder to the cup or to the brush.
Devices of this type are already known.
Thus, for example, U.S. Pat. No. 2,135,933 describes a device for driving in alternating rotation a cup for massaging the enamel. However, it is complex to produce and, above all, does not provide the necessary guarantee of leak-proofing for this type of use.
Many means of converting a continuous rotational movement into an alternating rotational movement are also known. French Pat. No. 1,455,922 in the Applicant's name is an example of this. In another technical field, but with a strictly identical function, Swiss Pat. No. 343,354 describes a device in which the axis of the drive stud is arranged inclined relative to the spindle to be driven.
These devices are of too fragile a structure for preventive treatment, and moreover they are not designed with sufficient leak-proofing for this use.
There is, therefore, a need for devices for preventive treatment which are both robust and leak-proof.